6/13/11

Barefoot Running: Overrated

This is Part 1 of a two-part Blog on the relationship between running form and footwear.  Click HERE for Part 2.

The run community is still in the midst of an explosion of enthusiasm!  More people are running for fitness, more runners are moving on to the Marathon and Half-Marathon distances, races are selling out quicker, and more races are appearing on the scene.  The tip of the iceberg in the latest installment of running enthusiasm is the hype surrounding barefoot running and minimalist run shoes.  The hype exists because there now appears to be an answer (a magic pill) to the riddles plaguing most runners, namely, injuries.

Every company that makes running sneakers has put out their version(s) of minimalist shoes (e.g., Nike's Free, Saucony's Kinvara).  On paper, the Vibram Five Finger models are the middle ground between running in sneakers and the other end of the spectrum, running barefoot.  The concept of a minimalist shoe isn't recent; just take a look at the sport of track & field, whose athletes have been wearing lightweight racing spikes (or flats) for decades.  I won't delve into the history of the running shoe industry; Danny Abshire, in his book Natural Running, has accomplished this task with a thorough and well-written chapter. 

The theory is that running barefoot, or running in minimalist shoes, will reduce injuries because the brain will sense less cushioning/padding in the heel, thereby naturally forcing the runner to land more on the midfoot.  The benefit to landing on the midfoot is a reduction in both braking forces and rotational forces, as compared to those forces that occur with a heel strike.  However, simply running barefoot (or minimalist) does not guarantee this correction from a heel strike to a midfoot strike.  There are factors at play that determine foot strike other than what's attached (or not attached) to your feet (more on that later).

*There are other benefits to a midfoot strike, compared to a heel strike, namely, faster cadence, faster speed (with all else being equal), and less strain on the muscles in the back of the leg.  These benefits will be addressed in Part 2 of this blog.

Notice I am not using the term "forefoot".  The term forefoot is getting lots of runners in trouble, as they are misinterpreting this to mean landing on the toes or even the ball of the foot without ever dropping the rear of the foot toward the ground.  This is not preferred unless you are a 100m – 400m sprinter.  Trying to run 5k through marathon distances on your toes, or the balls of your feet, is most likely going to strain your calves and/or the muscles in your feet, not to mention make you more unstable over uneven terrain.  To distinguish a forefoot strike from a midfoot strike (as is done in some empirical studies) is like splitting hairs, and a "forefoot" strike in these studies does not imply the runners were landing on their toes.  I argue that it's better to eliminate the term forefoot altogether, given that misinterpretation of the term has the potential for adverse effects.  Think "midfoot" and you'll be okay.

Getting back to the main issue, there should be a distinction between running barefoot and running in minimalist sneakers, for which I would argue much more support for the latter and reiterate the title of this Blog—running barefoot isn't something we should avoid, rather, it's just overrated.  There isn't anything you can accomplish running barefoot that you can't accomplish in minimalist sneakers, other than perhaps getting some nice puncture wounds from debris on the ground.  Granted, you can find nice stretches of grass to run on for some striders or take some laps on the grass field inside your local track.  However, I don't think any coach would promote those instances as legitimate stand-alone run training (it's simply not enough volume, agreed?).  So while I do think there can be a time and a place for barefoot running (hey, I grew up as a kid with a big backyard), I also think it does more harm than good, given the type of training an adult runner would try to implement with today's city streets and layout of state roads.

I felt that Abshire communicated similar points in Natural Running.  He acknowledges the proprioceptive benefits of barefoot running, but also acknowledges it's not very practical in the environment of today's cities.  As a dual-role coach-personal trainer, I promote the proprioceptive benefits of ditching the shoes during strength training, but I will assert that becoming sidelined with a freak injury while attempting to move into barefoot running is not worth the grief you will experience after being forced to take that unfortunate break in training.

Despite what I've written so far, injury from taking a wrong step here and there is not the more important argument against barefoot running.  For instance, there is some research to suggest running barefoot actually imposes more stress on the lower leg than running in shoes.  In a recent blog from the doctors/writers at The Science of Sport, they quoted the Lieberman study (which could have used more control groups) that showed barefoot running often led to no change in foot strike, and also led to increased impact forces when continuing to heel strike (as one might expect).  So, are we damned if we do, damned if we don't?  No.  And this is where I think minimalist run shoes pay the role of Equalizer.

As I stated previously, the claims that barefoot running grants runners a higher degree of proprioception can also be applied to lighter sneakers and those without much elevation in the heel.  This is where Abshire enters his Newton running shoe (although I'm a Saucony fan myself).  However, having stated the above, the key element to proper run mechanics, specifically, foot strike, is knowing how to run.  Most runners have to overcome some measurable disadvantage, like muscular weaknesses/imbalances, to gain good run mechanics.  In Lieberman's study, they referred to running "skill" or "familiarity" in relation to how much a runner is affected (if at all) by the transition to running barefoot.  The skill mentioned in this study was whether or not the runners had barefoot running experience, but there is additional "skill" required (in the traditional sense of the term) for good mechanics and that is knowing how to move your legs through the proper motion, starting from the instant the feet contact the ground.

I will paraphrase the finding of the above study and stretch it into the anecdotal evidence I see every day as a running coach, not to mention as an impartial observer to the hundreds of runners I see daily on the National Mall in DC.  There are throngs of runners heel striking while running barefoot, and in Vibrams, and in other minimalist shoes.  "Good" runners can run in construction boots or they can run barefoot, it doesn't matter.  When you have good running form (via foot strike) you can run virtually any number of miles in any type of footwear on any type of run surface and still have a very low predisposition to injury (name your injury).  This is attributable to the required hip flexibility and hamstring strength to move the legs through the correct range of motion; therefore, every stride hits the ground in the same fashion.  The footwear and the running surface, and even how many miles are being run, become irrelevant.  There's simply not much stress on the bodies of good runners, regardless of how fast they run (good runners come in all speeds).  However, admittedly, the pro athletes make better candidates to be a poster-child for all the new minimalist shoes.  Most of us have some catching up to do before we can safely and confidently say how wonderful the minimalist shoes have been to our bodies.  I would say it takes even longer before we can say the same thing about running barefoot.  Again, I point to the Sport Scientists Blog for a thorough explanation of why barefoot running is not for everyone, and could even be avoided altogether.

There are plenty of factors preventing the middle-50% of runners from achieving the sought after proper run mechanics.  Here are the 3 major factors contributing to proper running form and injury prevention: 1) strength and flexibility in the hamstring and hip, 2) what kind of shoes you run with ("traditional" vs. minimalist), and 3) the one factor everyone forgets about is quite simply knowing how to run.  If everyone ran like their 8-year-old cousin, there would be much fewer running injuries.  Call it a shameless plug for a running coach, but I'll explain what this means and address these 3 issues in Part 2 of this blog

Good luck!

Mike

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